Installation fixture for elastomer bands

ABSTRACT

An installation fixture adapted to mount an elastomer band in a mounting groove around a semiconductor substrate support used for supporting a semiconductor substrate in a plasma processing chamber is disclosed, which includes an annular ring having a vertically extending portion on an outer edge of the ring and adapted to receive the elastomer band, and a base plate configured to be attached to the annular ring, the base plate having a plurality of radially extending portions adapted to receive a plurality of mechanical fasteners at locations corresponding to mounting holes in the semiconductor substrate support.

FIELD OF THE INVENTION

The present disclosure relates to an installation fixture for installingan elastomer band around a substrate support and method of using theinstallation fixture.

BACKGROUND

Integrated semiconductor circuits have become the primary components ofmost electronics systems. These miniature electronic devices may containthousands of the transistors and other circuits that make up the memoryand logic subsystems of microcomputer central processing units and otherintegrated circuits. The low cost, high reliability and speed of thesecircuits have led them to become a ubiquitous feature of modem digitalelectronics.

The fabrication of integrated semiconductor circuits typically takesplace in a reactive ion etching system, such as a parallel plate reactoror inductively coupled plasma reactor. A reactive ion etching system mayconsist of an etching chamber with an upper electrode or anode and alower electrode or cathode positioned therein. The cathode is negativelybiased with respect to the anode and the container walls. The wafer tobe etched is covered by a suitable mask and placed directly on thecathode. A chemically reactive gas such as CF₄, CHF₃, CClF₃, HBr, Cl₂and SF₆ or mixtures thereof with O₂, N₂, He or Ar is introduced into theetching chamber and maintained at a pressure which is typically in themillitorr range. The upper electrode is provided with gas hole(s) whichpermit the gas to be uniformly dispersed through the electrode into thechamber. The electric field established between the anode and thecathode will dissociate the reactive gas forming plasma. The surface ofthe wafer is etched by chemical interaction with the active ions and bymomentum transfer of the ions striking the surface of the wafer. Theelectric field created by the electrodes will attract the ions to thecathode, causing the ions to strike the surface in a predominantlyvertical direction so that the process produces well-defined verticallyetched side walls.

Plasmas used for reactive ion etching are highly corrosive species andchamber component surfaces that are exposed to plasmas can degradequickly. Such degradation of chamber components is costly and can leadto contamination of chamber components or to contamination of asubstrate being processed in the chamber. Such degradation requiresreplacement of contaminated chamber components and/or cleaning of thecontaminated chamber components. Such replacement and/or cleaning of thechamber components leads to down-time of the processing chamber.

A substrate support comprising an electrostatic chuck (ESC) forelectrostatically clamping a substrate to the support is one suchchamber component that may undergo degradation due to exposure to aplasma environment. These types of substrate supports typically comprisea number of components adhered to one another. For example, the supportmay comprise a cooling plate, a heater element and/or a ceramic platebonded to one another by a suitable adhesive. To minimize degradationfrom exposure to the plasma environment, it is common to place anelastomer band around these components in order to protect the adhesivefrom direct exposure to the plasma environment, such as described incommonly-owned U.S. Patent Publication Nos. 2013/0097840, 2013/0117986and 2013/0263427. However, the elastomer band is then directly exposedto the plasma environment and suffers degradation therefrom. Theelastomer band also suffers degradation from compression forces underoperational conditions.

The manner in which an elastomer band is disposed around a substratesupport may also yield localized stresses in the elastomer band, whichleads to the elastomer band being further susceptible to degradationfrom exposure to the plasma environment. Typically, an elastomer band isdisposed around a substrate support by hand in a 5-point star-shapedpattern. Such a disposal pattern creates highly localized stress areasin the elastomer, which are weaker areas in the elastomer and subjectsthese areas to greater mass loss when exposed to a plasma environment,usually leading to cracking of the elastomer.

Thus, there is a need for an improved method of installing an elastomerband around a substrate support such that the elastomer banddemonstrates increased resistance to degradation from exposure to aplasma environment.

SUMMARY

An installation fixture adapted to mount an elastomer band in a mountinggroove around a semiconductor substrate support used for supporting asemiconductor substrate in a plasma processing chamber is disclosed, theinstallation fixture comprising: an annular ring having a verticallyextending portion on an outer edge of the ring and adapted to receivethe elastomer band; and a base plate configured to be attached to theannular ring, the base plate having a plurality of radially extendingportions adapted to receive a plurality of mechanical fasteners atlocations corresponding to mounting holes in the semiconductor substratesupport.

An elastomer band installation kit is disclosed, the kit comprising: aninstallation fixture adapted to mount an elastomer band in a mountinggroove around a semiconductor substrate support used for supporting asemiconductor substrate in a plasma processing chamber, the installationfixture comprising: an annular ring having a vertically extendingportion on an outer edge of the ring and adapted to receive theelastomer band; and a base plate configured to be attached to theannular ring, the base plate having a plurality of radially extendingportions adapted to receive a plurality of mechanical fasteners atlocations corresponding to mounting holes in the semiconductor substratesupport; and a plurality of mechanical fasteners each adapted to fitthrough through-holes of a substrate support and through thethrough-holes of the installation fixture.

A method of installing an elastomer band as a protective edge sealaround a portion of a semiconductor substrate support used forsupporting a semiconductor substrate in a plasma processing chamber isdisclosed, the method comprising: disposing an elastomer band around avertically extending portion of an installation fixture, theinstallation fixture comprising: an annular ring having a verticallyextending portion on an outer edge of the ring and adapted to receivethe elastomer band; and a base plate configured to be attached to theannular ring, the base plate having a plurality of radially extendingportions adapted to receive a plurality of mechanical fasteners atlocations corresponding to mounting holes in the semiconductor substratesupport; and sliding the elastomer band off the vertically extendingportion of the installation fixture and into a mounting groove in thesubstrate support adapted to receive the elastomer band.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of a processing chamber suitable forplasma etching semiconductor substrates.

FIG. 2 shows a cross-sectional view of a substrate support having anelastomer band within a mounting groove.

FIG. 3 shows a perspective view of an elastomer band installationfixture on a semiconductor substrate support in accordance with anexemplary embodiment.

FIG. 4 shows a perspective view of the elastomer band installationfixture in accordance with an exemplary embodiment.

FIG. 5 shows a cross-sectional view of the elastomer band installationfixture in accordance with an exemplary embodiment.

FIG. 6 shows a cross-sectional view of the elastomer band installationfixture in accordance with an exemplary embodiment.

DETAILED DESCRIPTION

Substrate supports for reactive ion etch processing chambers typicallyinclude a lower electrode assembly comprising an electrostatic clampinglayer on which a substrate or wafer is clamped during processing in aplasma processing chamber. The lower electrode assembly can also includevarious layers bonded to a temperature controlled base plate. Forexample, the assembly can include an upper ceramic layer incorporatingone or more electrostatic electrodes adhesively bonded to an upper sideof a heater plate, one or more heaters adhesively bonded to a bottom ofthe heater plate, and a temperature controlled base plate (hereafterreferred to as cooling plate) adhesively bonded to the heaters andheater plate. To protect the plasma-exposed adhesive bond layers, anedge seal, for example, an elastomer band can be disposed around thebond layers of the substrate support.

FIG. 1 shows a cross-sectional view of an exemplary plasma reactor 10for etching substrates. As shown in FIG. 1, the plasma reactor 10includes a plasma processing chamber 12, an antenna disposed above thechamber 12 to generate plasma, which is implemented by a planar coil 16.The RF coil 16 is typically energized by an RF generator 18 via amatching network (not shown). Such chambers are called inductivelycoupled plasma (ICP) chambers. To supply process gas to the interior ofthe chamber 12, there is provided a gas distribution plate or showerhead14, which preferably includes a plurality of holes for releasing gaseoussource materials, for example, the etchant source gases, into theRF-induced plasma region between the showerhead 14 and a semiconductorsubstrate or wafer 30 supported on a substrate support 100 comprisinglower electrode assembly 28. While an inductively coupled plasma reactoris shown in FIG. 1, the plasma reactor 10 can incorporate other plasmagenerating sources such as capacitive coupled plasma (CCP), microwave,magnetron, helicon, or other suitable plasma generating equipment, inwhich case the antenna is omitted.

The gaseous source materials may also be introduced into the chamber 12by other arrangements such as one or more gas injectors extendingthrough the top wall and/or gas ejection ports built into the walls ofchamber 12. Etchant source chemicals include, for example, halogens suchas Cl₂ and BCl₃ when etching through aluminum or one of its alloys.Other etchant chemicals (for example, CH₄, HBr, HCl, CHCl₃) as well aspolymer forming species such as hydrocarbons, fluorocarbons, andhydro-fluorocarbons for side-wall passivation of etched features mayalso be used. These gases may be employed along with optional inertand/or nonreactive gases.

In use, a wafer 30 is introduced into chamber 12 defined by chamberwalls 32 and disposed on the lower electrode assembly 28. The wafer 30is preferably biased by a radio frequency generator 24 (also typicallyvia a matching network). The wafer 30 can comprise a plurality ofintegrated circuits (ICs) fabricated thereon. The ICs, for example, caninclude logic devices such as PLAs, FPGAs and ASICs or memory devicessuch as random access memories (RAMs), dynamic RAMs (DRAMs), synchronousDRAMs (SDRAMs), or read only memories (ROMs). When the RF power isapplied, reactive species (formed from the source gas) etch exposedsurfaces of the wafer 30. The by-products, which may be volatile, arethen exhausted through an exit port 26. After processing is complete,the wafer 30 can be subjected to further processing and eventually dicedto separate the ICs into individual chips.

It can be appreciated that the reactor 10 can also be used for metal,dielectric and other etch processes. In plasma etch processing, the gasdistribution plate can be a circular plate situated directly below adielectric window in an ICP reactor or form part of an upper electrodeassembly in a CCP reactor called a parallel plate reactor wherein thegas distribution plate is a showerhead electrode oriented parallel to asemiconductor substrate or wafer 30. The gas distributionplate/showerhead electrode contains an array of holes of a specifieddiameter and spatial distribution to optimize etch uniformity of thelayers to be etched, for example, a photoresist layer, a silicon dioxidelayer and an underlayer material on the wafer.

An exemplary parallel-plate plasma reactor that can be used is adual-frequency plasma etch reactor (see, for example, commonly-ownedU.S. Pat. No. 6,090,304, which is hereby incorporated by reference inits entirety). In such reactors, etching gas can be supplied to ashowerhead electrode from a gas supply and plasma can be generated inthe reactor by supplying RF energy at different frequencies from two RFsources to the showerhead electrode and/or a bottom electrode.Alternatively, the showerhead electrode can be electrically grounded andRF energy at two different frequencies can be supplied to the bottomelectrode.

FIG. 2 shows a cross-sectional view of a portion of substrate support100 having various layers bonded together with exposed bond layerslocated in a mounting groove adapted to receive an edge seal, forexample, an elastomeric band 160. The substrate support 100 may also beadapted to receive a plurality of mechanical fasteners. The substratesupport 100 comprises a heater plate 130 comprised of a metal orceramic. An adhesive bonding layer 120 is disposed below the heaterplate 130 and bonds the heater plate 130 to the cooling plate 110.Another adhesive bonding layer 125 is disposed above the heater plate130 and bonds the heater plate 130 to the ceramic plate 135incorporating one or more electrostatic clamping electrodes. The ceramicplate 135 and the cooling plate 110 may have portions that extend beyondthe outermost portions of the heater plate 130 and the bonding layers120, 125 to form a mounting groove 145. The outermost portions of theheater plate 140 and the bond layers 120, 125 are substantially alignedwith respect to one another. Preferably, the ceramic plate 135 has alarger diameter than the heater plate 130 and the bonding layers 120,125.

In an exemplary embodiment, the cooling plate 110 can be configured toprovide temperature control by the inclusion of fluid channels (notshown) therein through which a temperature controlled liquid can becirculated. The cooling plate 110 is typically a metal base plate whichfunctions as the lower RF electrode in the plasma chamber. The coolingplate 110 preferably comprises an anodized aluminum or aluminum alloy.However, it can be appreciated that any suitable material, includingmetallic, ceramic, electrically conductive and dielectric materials canbe used. In an exemplary embodiment, the cooling plate 110 is formedfrom an anodized machined aluminum block. Alternatively, the coolingplate 110 could be of ceramic material with one or more electrodeslocated therein and/or on an upper surface thereof. In addition, thecooling plate 110 preferably has a uniform thickness from the center tothe outer edge or diameter thereof and is preferably a thin circularplate. The cooling plate 110 may comprise a series of though-holes 140for receiving mechanical fasteners which fasten substrate support 100 tothe processing chamber.

The heater plate 130 may be in the form of a metal or ceramic plate withat least one film heater coupled to a bottom of the metal or ceramicplate. The film heater can be a foil laminate (not shown), whichincludes a first insulation layer (e.g., dielectric layer), a resistiveheating layer (e.g., one or more strips of electrically resistivematerial) and a second insulation layer (e.g., dielectric layer). Theinsulation layers preferably consist of materials having the ability tomaintain its physical, electrical and mechanical properties over a widetemperature range including resistance to corrosive gases in a plasmaenvironment such as Kapton or other suitable polyimide films. Theresistive heating layer preferably consists of a high strength alloysuch as Inconel or other suitable alloy or anti-corrosion and resistiveheating materials. The film heater can be in the form of a laminate ofKapton, Inconel and Kapton having a total thickness of about 0.005 toabout 0.009 of an inch and more preferably about 0.007 of an inch thick.

The ceramic layer 135 is preferably an electrostatic clamping layer ofceramic material with an embedded electrode comprised of a metallicmaterial, such as W, Mo etc. In addition, the ceramic layer 135preferably has a uniform thickness from the center to the outer edge ordiameter thereof and is preferably a thin circular plate suitable forsupporting 200 mm, 300 mm or 450 mm diameter wafers. Details of a lowerelectrode assembly having an upper electrostatic clamping layer, heaterlayer and bonding layers are disclosed in commonly owned U.S. Pat. No.8,038,796 wherein the upper electrostatic clamping layer has a thicknessof about 0.04 inch, the upper bonding layer has a thickness of about0.004 inch, the heater plate comprises a metal or ceramic plate of about0.04 inch thickness and a heater film of about 0.01 inch thickness, andthe lower bonding layer has a thickness of about 0.013 to 0.04 inch.However, different thicknesses of the clamping layer, bond layers andheater layer can be selected to achieve desired process results.

The adhesive bonding layers 120 and 125 are preferably formed from a lowmodulus material such as an elastomeric silicone or silicone rubbermaterial. However, any suitable bonding material can be used. It can beappreciated that the thickness of adhesive layers 120 and 125 can varydepending on the desired heat transfer coefficient. Thus, the thicknessthereof can be uniform or non-uniform to provide a desired heat transfercoefficient based on manufacturing tolerances of the adhesive bondinglayers 120 and 125. The thickness of adhesive bonding layers 120 and 125can vary over its applied area by plus or minus a specified variable.Preferably, if the bond layer thickness does not vary by more than 1.5percent, the heat transfer coefficient between components of thesubstrate support 100 can be made substantially uniform. For example,for a substrate support 100, which includes an electrode assembly usedin the semiconductor industry, the adhesive bonding layers 120 and 125preferably have a chemical structure that can withstand a wide range oftemperatures. Thus, it can be appreciated that the low modulus materialcan comprise any suitable material, or combination of materials, such asa polymeric material compatible with a vacuum environment and resistantto thermal degradation at high temperatures (e.g., up to 500° C.). Inone embodiment, the adhesive bonding layers 120 and 125 may comprisesilicone and be between about 0.001 to about 0.050 of an inch thick andmore preferably about 0.003 to about 0.030 of an inch thick.

As shown in FIG. 2, a portion of the cooling plate 110 and the ceramicplate 135 can extend beyond an outermost portion of the heater plate130, the adhesive bond layers 120 and 125, thereby forming a mountinggroove 145 in the substrate support 100. The material(s) of adhesivebonding layers 120 and 125 are typically not resistant to the reactiveetching chemistry of semi-conductor plasma processing reactors andtherefore, should be protected to accomplish a useful operationlifetime. To protect the adhesive bonding layers 120 and 125, it hasbeen proposed to place an edge seal in the form of an elastomeric band160, into the mounting groove 145 to form a tight seal that preventspenetration of the corrosive gases of semi-conductor plasma processingreactors. See, for example, commonly owned U.S. Published ApplicationNos. 2013/0097840, 2013/0117986 and 2013/0263427.

The elastomer band 160 can be installed by hand in a 5-point star-shapedstretching pattern. Generally, a portion of the elastomer band 160 isinserted into a mounting groove and another portion of the elastomerband 160 is stretched and inserted into the mounting groove 145. Thisstretching process is repeated with subsequent portions of the elastomerband 160 that are away from the previously inserted portion until theelastomer band 160 is completely inserted into the mounting groove 145.However, such a method of inserting the elastomer band 160 leads tohighly localized stressed areas in the elastomer band 160. Thesestressed areas are weaker than other areas in the elastomer band 160 andare subject to greater mass loss when exposed to a plasma environment.The greater mass loss, in turn, leads to degradation, such as cracking,of the elastomer band 160, thereby necessitating replacement of theelastomer band 160.

FIG. 3 shows an installation fixture 200 that can be used to relievesuch stressed areas of an elastomer band 160 positioned on asemiconductor substrate support 100. As shown in FIG. 3, theinstallation fixture 200 can include an annular ring 210 having an inneredge 212, an outer edge 214, an upper surface 216, and a lower surface218 (FIG. 4). In accordance with an exemplary embodiment, the annularring 210 can also include a vertically extending portion 220 on theouter edge 214 of the annular ring 210 and adapted to receive anelastomer band 160.

The installation fixture 200 can also include a base plate 230 having anouter recess 232 (FIG. 4) configured to be attached to the annular ring210. The base plate 230 can also include a plurality of radiallyextending portions 240 adapted to receive a plurality of mechanicalfasteners 260 at locations corresponding to mounting holes 140 in thesemiconductor substrate support 100. In accordance with an exemplaryembodiment, the base plate 230 preferably has an upper surface 234having an upper inner surface 236, an outer recess 232 (FIG. 4), whichis formed by a vertical wall 237 connecting the inner surface 236 to alower outer surface 238. The lower outer surface 238 is relativelyplanar. In accordance with an exemplary embodiment, the base plate 230preferably is a solid stepped plate.

In accordance with an exemplary embodiment, the base plate 230 alsoincludes an inner recess 239 (FIG. 6) having a circular outer diameterformed on a lower surface 233 of the base plate 230. The lower surface233 of the base plate 230 can include an annular outer surface 235, avertical wall 241 extending upward to a lower inner surface 243. Therecess 239 is adapted to be located above an outer portion or peripheryof an upper surface of substrate support 100. For example, in accordancewith an exemplary embodiment, the outer annular surface 235 of the baseplate 230 can be adapted to be received on and contact the ceramic layer135 at an outer portion or periphery thereof. In accordance with anexemplary embodiment, the depth of the recess 239 is not particularlylimited, so long as a sufficient spacing is provided between the lowerinner surface 243 disposed closest to the surface of the ceramic layer135. For example, the recess 239 can have a depth between about0.01-0.05 inch, for example, a depth of about 0.025 inch. The base plate230, for example, can have a thickness between the upper inner surface236 and the lower inner surface 243 of about 0.50 to 0.60 inches, forexample, about 0.524 inches.

In accordance with an exemplary embodiment, the installation fixture 200preferably has an annular shape thereto and adapted to mount anelastomer band 160 in a mounting groove 145 around a semiconductorsubstrate support 100. For example, in accordance with an exemplaryembodiment, using the installation fixture 200 to install an elastomerband 160 around the substrate support 100 can reduce local stresses inthe elastomer band 160 and reduce the chances of the elastomer band 160cracking under operational conditions, for example, when exposed to aplasma environment. In addition, the use of the installation fixture 200can lead to an elastomer band 160 with a longer operational lifetimewhen compared to those installed by hand in a 5-point star-shapedstretching pattern. In addition, a two-piece design as disclosed hereincan provide a replaceable annular ring 210, which can be size dependenton the outer diameter of the semiconductor substrate support 100. Inaddition, a single base plate 230 can be used for the different sizedannular rings 210. For example, in accordance with an exemplaryembodiment, the annular ring 210 can be replaced after a certain numberof uses and/or if damaged during use or transport. The installationfixture 200 as disclosed herein can also provide for improved alignmentof the elastomer band 160 around the semiconductor substrate support100, which can provide improved performance of the plasma reactor 10.

In accordance with an exemplary embodiment, each of the plurality ofradially extending portions 240 can include a through-hole 242. Inaccordance with an exemplary embodiment, the radially extending portions240 are adapted to receive a plurality of mechanical fasteners 260 atlocations corresponding to mounting holes in the semiconductor substratesupport 100. Preferably, the base plate 230 of the installation fixture200 comprises four radially extending portions 240. The spacing of eachradially extending portion 240 around the installation fixture 200 isnot particularly limited, for example, each radially extending portion240 can be disposed from about 45° to about 135° from neighboringradially extending portions 240. Alternatively, for example, eachradially extending portion 240 can be disposed about 90° fromneighboring radially extending portions 240.

The inner 211 and outer diameter 213 of the annular ring 210 of theinstallation fixture 200 are not particularly limited, so long asinstallation fixture 200 is sized accordingly with respect to the sizeof the substrate support 100. For example, the annular ring 210 can havean outer diameter 213 with respect to an outermost surface of thevertically extending portion 220 of between about 11.0 to 12.0 incheswith respect a substrate support designed for processing substrates orwafers with a 300 mm diameter. Preferably, the outer diameter 213 isabout 11.7 inches. With respect to processing substrates or wafers witha diameter less than 300 mm, such as 200 mm, or greater than 300 mm,such as 450 mm, the diameters of installation fixture 200 are scaledaccordingly. The outer diameter 213 of the annular ring 210 can also bedetermined by the diameter of elastomer band 160 (not shown) and theband's stretching tolerance.

FIG. 4 shows another perspective of the installation fixture 200, whichincludes the annular ring 210 and the base plate 230, and a protectivecover 300. As shown in FIG. 4, the annular ring 210 has an annularrecess 226 on an inner portion 228 of the upper surface 216 of theannular ring 210. The annular recess 226 is adapted to be located abovean outer portion or periphery of an upper surface of substrate support100. For example, the upper surface 216 of the annular ring 210 can beadapted to be received on and contact the ceramic layer 135 at an outerportion or periphery thereof. In accordance with an exemplaryembodiment, the un-recessed portions 224 of the upper surface 216 cancontact an outer periphery of ceramic layer 135. In accordance with anexemplary embodiment, the depth of the recess 226 is not particularlylimited, so long as a sufficient spacing is provided between ahorizontal surface of the inner portion 228 disposed closest to theoutermost surface of ceramic layer 135. For example, the recess 226 canhave a depth between about 0.01-0.05 inch, for example, a depth of about0.025 inch.

In accordance with an exemplary embodiment, the vertical extendingportion 220 may comprise an angled tip (not shown) at a free end 221thereof. Preferably, the angle of the angled tip is between about 10°and about 45° and most preferably about 20°. The through-holes 242 ofthe radially extending portion 240 of the base plate 230 are adapted toalign with though-holes 140 of cooling plate 110.

In accordance with an exemplary embodiment, a protective cover 300 canbe provided with the installation fixture 200 to protect the verticalextending portion 220 (or lip) of the annular ring 210, for example,during non-use and/or transport of the fixture 200. The protective cover300 preferably has a recessed portion 310 configured to fit around andover the vertical extending portion 220 and the outer edge 214 of theannular ring 210. In addition, the recessed portion 310 can beconfigured to contact the upper surface 216 of the annular ring 210.

As shown in FIG. 4, a mechanical fastener 260 can be used forrotationally constraining installation fixture 200 with respect tosubstrate support 100. The mechanical fastener 260 can be a locking pinor bolt adapted to fit through both the through-holes 140 of thesubstrate support 100 and the through-holes 242 of installation fixture200. In accordance with an exemplary embodiment, the mechanical fastener260 can be cylindrical or hemi-cylindrical in shape. The mechanicalfastener 260 can include a plurality of portions along its length thathave varying diameters. For example, one end portion 266 of mechanicalfastener 260 may comprise the largest diameter, one end portion 262 ofmechanical fastener 260 may comprise the smallest diameter and a centralportion 264 may comprise an intermediate diameter. However, themechanical fastener 260 can be shaped other than cylindrical, such assquare, tapered or polygonal. Preferably, end surfaces of the mechanicalfastener 260 are recessed and adapted to receive the head of a bolt thatfastens the substrate support 100 to a work-piece, such as a table orchamber wall. For example, if the bolts that fasten substrate support100 to the work-piece are dome-shaped, then end surfaces of mechanicalfastener 260 can be recessed with a similar dome-shape or similarconcavity. If the bolts that fasten substrate support 100 to thework-piece are hexagonally-shaped, then the end surfaces of themechanical fastener 260 can be recessed with a similar hexagonal shape.

When the through-holes 140, 242 are aligned, a mechanical fastener 260can be inserted through each set of aligned through-holes 140, 242 suchthat installation fixture 200 is rotationally constrained with respectto substrate support 100. The dimensions of mechanical fastener 260 arenot particularly limited, so long as it can sufficiently rotationallyconstrain installation fixture 200 when installed.

FIG. 5 shows a cross-sectional view of the elastomer band installationfixture 200 in accordance with an exemplary embodiment. As shown in FIG.5, the base plate 230 can include a plurality of holes 252 configured toreceive a screw (or fastener) 250, which attaches the base plate 230 tothe annular ring 210 via a corresponding recess 222 on the lower surface218 of the annular ring 210. For example, in accordance with anexemplary embodiment, the base plate 230 can include three or moreequally spaced holes 252 aligned with corresponding recesses 222 on thelower surface 218 of the annular ring 210. The spacing of each of theholes 252 around the base plate 230 is not particularly limited andpreferably, for example, each hole 252 can be disposed about 120° fromthe neighboring hole 252 with corresponding aligned recess 222 in thelower surface of the annular ring 210. In accordance with an exemplaryembodiment, the fastener 250 is made from polyetheretherketone (PEEK).

FIG. 6 shows a cross-sectional view of the elastomer band installationfixture 200 in accordance with an exemplary embodiment. In accordancewith an exemplary embodiment, the annular ring 210 is configured to fitaround an outer vertical wall 237, which connects the upper surface 236of the base plate 230 to the outer lower surface 238 of the base plate230 and on top of the outer recess 232 of the base plate 230. As shownin FIG. 6, the base plate 230 also includes an inner recess 239 formedon the lower surface 233 of the base plate 230.

In accordance with an exemplary embodiment, the annular ring 210 and thebase plate 230 of installation fixture 200 can each be made from alow-friction plastic material such as polyethylene terephthalate (PET)or a fluorocarbon, for example, TEFLON® (PTFE orpolytetrafluoroethylene, manufactured by DuPont). Alternatively, theannular ring 210 and the base plate 230 of the installation fixture 200can be made from other materials, such as quartz, ceramic, metal orsilicon. Methods of making installation fixture 200 are not particularlylimited. For example, the annular ring 210 and the base plate 230 of theinstallation fixture 200 can be machined from a block or annular pieceof starting material. Alternatively, the annular ring 210 and the baseplate 230 of the installation fixture 200 can be injection molded. Inaccordance with an exemplary embodiment, the annular ring 210 is made ofPTFE or Teflon (Polytetrafluoroethylene) and the base plate 230 is madeof polyethylene terephthalate (PET).

In use, the end portion with the largest diameter of each mechanicalfastener 260 can be secured into each through-hole 140 of cooling plate110. Next, the installation fixture 200 can be located over the ceramiclayer 135 of the substrate support 100 such that each radially extendingportion 240 with through-holes 242 is aligned with each mechanicalfastener 260 placed into each through-hole 140 of cooling plate 110 andun-recessed portion 224 of the inner portion 228 contacts an outerperiphery of ceramic layer 135. The installation fixture 200 can then bedisposed over the ceramic layer 135 with the free end 221 of thevertically extending portion 220 facing away from ceramic layer 135,such that the through-holes 242 of installation fixture 200 are disposedaround the central portions 264 of the mechanical fasteners 260. Theinstallation fixture 200 can be rotationally constrained with respect tosubstrate support 100.

In accordance with an exemplary embodiment, an elastomer band 160 can beplaced around an outermost circumference of vertically extending portion220 by stretching the elastomer band 160 to fit the circumference.Preferably, elastomer band 160 is not stretched more than 2% of itscircumference when placed around an outermost circumference of thevertically extending portion 220, as doing so may permanently distortits elasticity. The elastomer band 160 may be relieved of its localizedinternal stresses by rotation back and forth around installation fixture200. The elastomer band 160 may be rotated back and forth aroundinstallation fixture 200 by at least about 20°. The elastomer band 160can be rotated back and forth around installation fixture 200 by atleast about 20°-90° and more preferably, by at least about 180°. Forexample, the rotation back and forth is carried out at least twice, andmore preferably, at least 4-5 times.

After the elastomer band 160 has been rotated back and forth and itslocalized internal stresses relieved, installation fixture 200 and themechanical fasteners 260 are inverted 180° about the horizontal plane ofinstallation fixture 200 and re-secured to substrate support 100. Theinstallation fixture 200 and the mechanical fasteners 260 can be flippedupside down such that the free end 221 is downward facing and proximatemounting groove 145. The un-recessed portions of inner portion 228contact an upper surface of an outer periphery of ceramic layer 135. Theelastomer band 160 is then slid off of vertically extending portion 220of installation fixture 200 and into mounting groove 145.

After the elastomer band 160 has been placed into mounting groove 145,it may be required to press elastomer band 160 further into mountinggroove 145. It is noted that the method described above installselastomer band 160 around a substrate support 100 while the substratesupport is disposed either inside or outside a processing chamber. Dueto ease of installation, it is preferable to install elastomer band 160around substrate support 100 while substrate support 100 is disposedoutside of a processing chamber. For example, when outside of aprocessing chamber, substrate support 100 may be mechanically fastenedto a work-piece, such as a table, for installation of elastomer band160. When inside of a processing chamber, substrate support 100 may alsobe mechanically fastened to a work-piece, such as a chamber wall, forinstallation of elastomer band 160.

The elastomer band 160 can be constructed from any suitablesemiconductor processing compatible material. For example, the elastomerband 160 is preferably constructed of curable fluoroelastomericfluoropolymers (FKM) capable of being cured to form a fluoroelastomer orcurable perfluoroelastomeric perfluoropolymers (FFKM) can be used. Theelastomer band 160 is preferably comprised of a material having highchemical resistance, low and high temperature capability, resistance toplasma erosion in a plasma reactor, low friction, and electrical andthermal insulation properties. A preferred material is aperfluoroelastomer having a Shore A durometer hardness including, butnot limited to, 60 to 85 and a specific gravity including, but notlimited to 1.9 to 2.1 such as PERLAST available from Perlast Ltd.Another band material is KALREZ available form DuPont PerformanceElastomers. PERLAST and KALREZ are FFKM elastomers. The shape of theelastomer band 160 is also not particularly limited and the elastomerbands may be circular, square or rectangular in cross-section. Theelastomer bands 160 may also have an irregularly shaped cross-section,such as rectangular cross-section with a concave outer surface asdisclosed in commonly owned U.S. Application Patent Publication No.2013/0097840.

When the word “about” is used in this specification in connection with anumerical value, it is intended that the associated numerical valueinclude a tolerance of ±10% around the stated numerical value.

Moreover, when the words “generally”, “relatively”, and “substantially”are used in connection with geometric shapes, it is intended thatprecision of the geometric shape is not required but that latitude forthe shape is within the scope of the disclosure. When used withgeometric terms, the words “generally”, “relatively”, and“substantially” are intended to encompass not only features which meetthe strict definitions but also features which fairly approximate thestrict definitions.

Although the present invention has been described in connection withpreferred embodiments thereof, it will be appreciated by those skilledin the art that additions, deletions, modifications, and substitutionsnot specifically described can be made without departing from the spiritand scope of the invention as defined in the appended claims.

What is claimed is:
 1. An installation fixture adapted to mount anelastomer band in a mounting groove around a semiconductor substratesupport used for supporting a semiconductor substrate in a plasmaprocessing chamber, the installation fixture comprising: an annular ringhaving a vertically extending portion on an outer edge of the ring andadapted to receive the elastomer band; and a base plate configured to beattached to the annular ring, the base plate having a plurality ofradially extending portions adapted to receive a plurality of mechanicalfasteners at locations corresponding to mounting holes in thesemiconductor substrate support, and the base plate including an outerrecess on an upper surface of the base plate configured to receive alower surface of the annular ring.
 2. The installation fixture of claim1, comprising: an annular recess on an inner portion of an upper surfaceof the annular ring.
 3. The installation fixture of claim 2, wherein theannular recess is adapted to be located above an upper surface of thesemiconductor substrate support.
 4. The installation fixture of claim 1,wherein the base plate has an inner recess on a lower surface of thebase plate, and wherein the inner recess is adapted to be located abovean upper surface of the semiconductor substrate support.
 5. Theinstallation fixture of claim 1, wherein the base plate includes aplurality of holes each configured to receive a fastener, which attachesthe base plate to the annular ring.
 6. The installation fixture of claim1, wherein the vertically extending portion has an angled tip at a freeend thereof.
 7. The installation fixture of claim 1, wherein the baseplate has a generally annular outer diameter.
 8. The installationfixture of claim 1, wherein the annular ring is made ofpolytetrafluoroethylene (PTFE) and the base plate is made ofpolyethylene terephthalate (PET).
 9. An elastomer band installation kit,the kit comprising: an installation fixture adapted to mount anelastomer band in a mounting groove around a semiconductor substratesupport used for supporting a semiconductor substrate in a plasmaprocessing chamber, the installation fixture comprising: an annular ringhaving a vertically extending portion on an outer edge of the ring andadapted to receive the elastomer band; and a base plate configured to beattached to the annular ring, the base plate having a plurality ofradially extending portions with through-holes adapted to receive aplurality of mechanical fasteners at locations corresponding to mountingholes in the semiconductor substrate support, the base plate includingan outer recess on an upper surface of the base plate configured toreceive a lower surface of the annular ring; and a plurality ofmechanical fasteners each adapted to fit through the mounting holes ofthe substrate support and through the through-holes of the installationfixture.
 10. The kit of claim 9, comprising: an annular recess on aninner portion of an upper surface of the annular ring.
 11. The kit ofclaim 10, wherein the annular recess is adapted to be located above anupper surface of the semiconductor substrate support.
 12. The kit ofclaim 9, wherein the base plate has an inner recess on a lower surfaceof the base plate, and wherein the inner recess is adapted to be locatedabove an upper surface of the semiconductor substrate support.
 13. Thekit of claim 9, wherein the base plate includes a plurality of holeseach configured to receive a fastener, which attaches the base plate tothe annular ring.
 14. The kit of claim 9, wherein the verticallyextending portion has an angled tip at a free end thereof.
 15. The kitof claim 9, wherein the base plate has a generally annular outerdiameter.
 16. The kit of claim 9, wherein the annular ring is made ofpolytetrafluoroethylene (PTFE) and the base plate is made ofpolyethylene terephthalate (PET).
 17. The kit of claim 9, comprising: aprotective cover configured to fit around and over the verticalextending portion and the outer edge of the annular ring.
 18. A methodof installing an elastomer band as a protective edge seal around aportion of a semiconductor substrate support used for supporting asemiconductor substrate in a plasma processing chamber, the methodcomprising: disposing an elastomer band around a vertically extendingportion of an installation fixture, the installation fixture comprising:an annular ring having a vertically extending portion on an outer edgeof the ring and adapted to receive the elastomer band; and a base plateattached to the annular ring, the base plate having a plurality ofradially extending portions and a plurality of mechanical fasteners inmounting holes in the semiconductor substrate support, the base plateincluding an outer recess on an upper surface of the base plateconfigured to receive a lower surface of the annular ring; and slidingthe elastomer band off the vertically extending portion of theinstallation fixture and into a mounting groove in the substrate supportadapted to receive the elastomer band.